To digitise a new survey, select File | New and you will see the New dialog. Give the survey a name and enter or select (using the [...] button) the image file that contains the survey to be digitised. Click Ok.

You then see the image file on screen.

Use the mouse scroll wheel (or the buttons) to zoom and click+drag to pan

Use the options from the actions menu to

digitise the end points of the scale bar

digitise the end points of the north arrow (from south to north)

Set a grid point for a known position on the survey.

Then you can choose Action | Digitise . You will be prompted for a traverse name (a digitised survey can have multiple traverses) once entered you can start digitising. Pressing Ctrl-Z undoes the last point.

File | Save at any point saves your work

To continue editing a survey can be loaded, and selecting the option to digitise an existing traverse continues with that traverse.